Well,

All I can tell is that I had the same problem on a Mac Laptop. I taped over the ground pin of the power supply as well and it did not work but it definitely worked when I CUT the ground wire in the main plug. (220V) You should give it a try.

Alex On Thursday, March 13, 2003, at 10:34 pm, TimBlechmann@gmx.net wrote:

hi,

i've got some problems connecting my laptop (acer aspire) with an amp: if i am using the power supply i am getting noises on the sound cards. both on the onboard and on the m-audio quattro. i searched the list archive and tried out some hints like putting tape over the ground pins and so on. without success.

i thought about the following possibilities:

1. a new (better) power supply

2. "cleaning" the power supply with some huge condensers. does who had

this problem tried this? i don't know if it's to fast to clean the tension peaks.

3. since i've got the same problem using the usb sound card, i thought

about using a usb connection without the power (5V) connection. i don't think that the quattro will get the information from the data connection...

if anyone has tried one of these possibilities or maybe have another idea it would be great if you let me know...

thanx a lot tim

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Hallo, TimBlechmann@gmx.net hat gesagt: // TimBlechmann@gmx.net wrote:

i've got some problems connecting my laptop (acer aspire) with an amp: if i am using the power supply i am getting noises on the sound cards. both on the onboard and on the m-audio quattro. i searched the list archive and tried out some hints like putting tape over the ground pins and so on. without success.

i thought about the following possibilities:

1. a new (better) power supply

2. "cleaning" the power supply with some huge condensers. does who had this

problem tried this? i don't know if it's to fast to clean the tension peaks.

3. since i've got the same problem using the usb sound card, i thought about

using a usb connection without the power (5V) connection. i don't think that the quattro will get the information from the data connection...

if anyone has tried one of these possibilities or maybe have another idea it would be great if you let me know...

Cutting ground on the power supply can really hurt you, so don't do it. I was bitten by the same problem on my Acer Travelmate. I read about a lot of things regarding this and I put some links on my WikiWeb at http://footils.org/cgi-bin/cms/pydiddy/wiki/GroundLoop

I found out, that my ground loop was easy to get rid of, actually. I had my main non-mobil computer connected to the same amp as the Laptop/Quattro combo. As soon as I disconnected my main PC, the humming went away.

This might work for you in a similar setup, so first try disconnecting everything else from the amp, like CD players, guitars or what ever.

Another solution might be going through a so called direct input box or DI-box. This disconnects ground from the audio-cables, *not* ground from the laptop's power supply. There also is a ready solution available with the "Monacor FGA-40" device, BestellNr.06.4370 You might be able to buy it in a car-audio-shop.

Then I also mailed Acer if the could send me another power connector without ground. They told me, that they are not allowed to do that in Germany by law.

ciao

Frank Barknecht _ ______footils.org__